his compact computer is smaller than the standard and midsize tower PCs that fit under your desk, making it ideal for limited work areas. Small case designs vary, too. However, such PCs tend to be underpowered (especially on gaming), and mini cases also have few available expansion slots and drive bays. Generally you'll have to expand the system via USB, FireWire, or eSATA peripherals, so make sure your compact system has a large number (and assortment) of ports.